Analog Devices Inc./Maxim Integrated MAX6429KSUR+T

Overview

MAX6429KSUR+T from Maxim Integrated is a factory-trimmed single-output battery monitor IC for Li+ and alkaline/NiMH/NiCd power supplies, featuring 2.0V low-threshold, 2.7V high-threshold, 140ms LBO timeout, 1µA supply current, and push-pull active-low LBO output in SOT23-3 package - used to trigger low-power mode or system shutdown in portable medical devices and MP3 players.

For engineers reviewing the MAX6429KSUR+T datasheet, MAX6429KSUR+T pinout, MAX6429KSUR+T application, or MAX6429KSUR+T equivalent, this page delivers verified threshold voltages, timeout behavior, supply current vs. temperature, LBO logic state down to 1.0V, and direct comparison with functionally aligned alternatives for battery-state decision circuitry.

Technical Context

The MAX6429KSUR+T implements a dual-comparator architecture with internal 615mV reference, fixed hysteresis between VLTH = 2.0V and VHTH = 2.7V (±2.5%), and built-in 140ms minimum timeout logic that prevents premature re-enabling of microprocessor or DC/DC converter after voltage recovery. It operates from 1.0V to 5.5V supply and guarantees valid LBO state down to BATT = 1.0V.

No external components are required. The device uses BATT as both input and power source, with GND and LBO forming the complete 3-pin interface. Its BiCMOS process ensures stable trip-point accuracy across –40°C to +85°C and immunity to short battery transients.

Key Specifications

Pinout & Package

SOT23-3 package (3-pin, 1.4mm × 2.9mm × 1.1mm), lead-free, tape-and-reel format. Pin 1 = BATT, Pin 2 = LBO, Pin 3 = GND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery-monitoring applications.

Compared with MAX6428KSUR+T, the MAX6429KSUR+T offers earlier low-battery assertion (2.0V vs. 2.1V) and lower recovery threshold (2.7V vs. 2.8V), enabling longer safe runtime in low-voltage alkaline systems; versus TLV7031DBVR, it delivers integrated timing, reference, and ultra-low power without external components.

Availability

MAX6429KSUR+T is available at Aetrix Electronics and suitable for portable medical sensors, MP3 players, wireless pagers, and cordless telephones requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for MAX6429KSUR+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for power, sensing, and interface applications, with emphasis on low-power, high-reliability solutions for portable and industrial systems.

The MAX6427–MAX6438 family was engineered specifically for battery-state monitoring in space-constrained, energy-sensitive devices - delivering factory-trimmed or user-adjustable thresholds with integrated hysteresis and timeout logic in minimal footprints.

FAQ

What is the exact low and high threshold voltage for MAX6429KSUR+T?

The MAX6429KSUR+T has a factory-trimmed low threshold (VLTH) of 2.0V ±2.5% and high threshold (VHTH) of 2.7V ±2.5%. These values are laser-trimmed during production and do not require external components. The 2.0V/2.7V pair is optimized for single Li+ cells and two-cell alkaline/NiMH systems, and is confirmed in Maxim's MAX6427–MAX6438 datasheet Table 1 (code "OR" suffix).

Does MAX6429KSUR+T require external resistors or capacitors?

No, MAX6429KSUR+T requires no external components. It integrates a precision 615mV reference, dual comparators, hysteresis logic, and 140ms timeout circuitry. The SOT23-3 footprint connects only BATT, GND, and LBO - eliminating resistor dividers, timing capacitors, and pull-up resistors required by discrete comparator solutions.

What is the minimum battery voltage at which MAX6429KSUR+T guarantees valid LBO logic?

MAX6429KSUR+T guarantees valid LBO logic state down to BATT = 1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. This ensures reliable low-battery signaling even during deep discharge of alkaline or NiMH cells, a key requirement for data retention and safe shutdown in portable medical devices.

How does the 140ms timeout period in MAX6429KSUR+T improve system reliability?

The 140ms minimum timeout in MAX6429KSUR+T prevents LBO deassertion until the battery voltage remains above VHTH for ≥140ms. This avoids chattering during transient recovery (e.g., after load removal), ensuring microcontrollers and DC/DC converters activate only after stable supply conditions - critical for avoiding boot failures or corrupted memory writes.

Is MAX6429KSUR+T pin-compatible with other devices in the MAX6427–MAX6438 family?

MAX6429KSUR+T shares the SOT23-3 package and identical pinout (BATT–LBO–GND) with MAX6427 and MAX6428 variants. However, it is not pin-compatible with SOT143-4 (MAX6430–MAX6432), SOT23-5 (MAX6433–MAX6435), or SOT23-6 (MAX6436–MAX6438) variants due to differing pin counts and functions such as HTHIN/LTHIN/VDD.